pruneemptydirs: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pruneemptydirs - from package: kdesdk

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pruneemptydirs - from package: kdesdk-scripts

You may install the required package with command apt-get install {package}
Error in other languages:
pruneemptydirs: bevel nie gevind nie
pruneemptydirs: comandă negăsită
pruneemptydirs: comando não encontrado
pruneemptydirs: commande introuvable
pruneemptydirs: command not found
pruneemptydirs: käsku ei ole
pruneemptydirs: không tìm thấy lệnh
pruneemptydirs: komanda nerasta
pruneemptydirs: Kommando nicht gefunden.
pruneemptydirs: kommandot finns inte
pruneemptydirs: komut yok
pruneemptydirs: nie znaleziono polecenia
pruneemptydirs: níor aimsíodh an t-ordú
pruneemptydirs: no se encontró la orden
pruneemptydirs: no s'ha trobat l'ordre
pruneemptydirs: opdracht niet gevonden
pruneemptydirs: parancs nem található
pruneemptydirs: perintah tidak ditemukan
pruneemptydirs: príkaz nenájdený
pruneemptydirs: příkaz nenalezen
pruneemptydirs: команда не найдена
pruneemptydirs: командата не е открита
pruneemptydirs: 命令找不到
pruneemptydirs: コマンドが見つかりません